Experimental Research On Adsorption Performance Of Composite Silica Gel Supported Calcium Chloride Sorbents

Whether the adsorption refrigeration technology can be widely used in industry largely depends on the selection of refrigeration work pair, because its adsorption capacity in a cycle and thermal properties are of great influence for every performance parameters of the system and materials and cost of the equipment.In this paper, a series of typical silica gel-based calcium chloride composites adsorbents were prepared, which were carried out by excess solution method with the use of A-type and C-type silica gel as the support of calcium chloride. On one hand, it could scatter the calcium chloride by Silica gel skeleton and solve the problem of expansion and agglomeration during working process. On the other hand, it could improve the adsorption performance of adsorbent by the strong ability of adsorption of calcium chloride.An experimental apparatus is designed and set up to investigate the sorption performance of the composites adsorbents, the adsorption rate curves and adsorption capacity curves of silica gel and its composite adsorbents are measured accurately under vacuum depending on the weighing method. The way of loading and working condition of the adsorbents during testing are similar to the actual model machine, so the efficiency of heat and mass transfer is more familiar to the actual model refrigeration, as a result, the experimental data has more reference value. This experimental apparatus designs a kind of detachable adsorbent bed in order to improve the efficiency of experiment by disassembling the adsorption bed frequently.Through the experiment we could infer that:after the modifying by calcium chloride, both the adsorption capacity and the adsorption rate of the composite sorbents supported by C-type silica gel have a significantly increase, and even better than the pure A-type silica gel, and within certain limits,the higher of the content of calcium chloride in the composite sorbents, the more obvious of the increase effect of adsorption rate and adsorption capacities; the A-type silica gel is different, its adsorption performance do not have any increase, but decreased in turn. In conclusion, the C-type silica gel whose pore size greater than7nm is recommended when prepared silica gel-based calcium chloride composite sorbents by impregnation method, rather than the A-type silica gel. The research in this paper has an important reference value for the design, of model refrigeration, which takes silica gel-based calcium chloride composite adsorbents-water as working pairs, it is also of great significance for the apply on ship of solid adsorption refrigeration system.